Along with its needed effects, ascorbic acid (the active ingredient contained in Sunkist Vitamin C) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur while taking ascorbic acid:

Some side effects of ascorbic acid may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Renal

Nervous system

The manufacturer reports temporary dizziness and faintness may be associated with too rapid of a rate during intravenous administration.[Ref]

Nervous system side effects have included dizziness, faintness, fatigue, and headache in less than 1% of patients. Migraine headache has also been reported.[Ref]

Other

Conditional scurvy is reported to occur following excessive doses of ascorbic acid (the active ingredient contained in Sunkist Vitamin C) over a prolonged period of time. The mechanism of action for this condition is thought to be that large doses of ascorbic acid condition the patient over time for rapid clearance of ascorbic acid resulting in scurvy. The plasma levels of ascorbic acid appear to remain within normal limits. The actual existence of conditional scurvy remains controversial.[Ref]

Other side effects have included flank pain in less than 1% of patients. Conditional scurvy has also been reported.[Ref]

Gastrointestinal

Gastrointestinal side effects have included nausea, diarrhea, abdominal cramps, and esophagitis.[Ref]

Nausea, diarrhea, and abdominal cramps appears to be associated with doses exceeding 2 g per day, although there have been some reports with as little as 1 g per day.

Esophagitis appears to be associated with prolonged or increased contact of ascorbic acid tablets with the esophageal mucosa.[Ref]

Hematologic

The majority of hemolysis reports have been associated with patients who have concurrent glucose-6-phosphate dehydrogenase deficiency.[Ref]